Lightweight, out of the box server setup with Busybox httpd
Introduction
busybox is a lightweight executable that contains tiny versions of common UNIX utilities. Compared to their counter parts the busybox versions have fewer arguments making busybox easy to work with. busybox also comes with a httpd utility to listen to incoming HTTP requests, this can be used as a lightweight server out of the box without having to install a lot of dependencies for alternatives.
Previous Work
I have used busybox’s httpd as a CGI server1 as a part of a challenge to create a lightweight server. In the follow up article which I wrote (Nimalan, 2020), I mentioned that this could be used as a reverse proxy.
Idea
A small problem though is that the amount of documentation specific to busybox httpd is limited, which means we have to rely on the source code.
FEATURE_HTTPD_PROXY2 needs to be enabled for reverse proxy, we build busybox with httpd reverse proxy enabled by setting this option with make menuconfig
With the newly compiled busybox we can specify reverse proxy config in http
# httpd.conf
P:/url:[http://]hostname[:port]/new/path
References
- BusyBox httpd.
https://www.busybox.net/downloads/BusyBox.html#httpd. [Online; accessed 4-Jan-2021] - BusyBox httpd source.
https://git.busybox.net/busybox/tree/networking/httpd.c?id=97c00ae13439ad8114ad7d2150c8dde464f04eb1. [Online; accessed 4-Jan-2021] - Apache httpd.
https://httpd.apache.org/docs/2.4/programs/httpd.html. [Online; accessed 4-Jan-2021] - Nimalan, 2020. A Bare Minimal Http Server.
https://mark1626.github.io/posts/2021/01/11/bare-minimal-http-server/. [Online; accessed 11-Jan-2021]